Magnetic Field Dependence of Blocking Temperature in Oleic Acid Functionalized Iron Oxide Nanoparticles
IR@NPL: CSIR-National Physical Laboratory, New Delhi
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| Title |
Magnetic Field Dependence of Blocking Temperature in Oleic Acid Functionalized Iron Oxide Nanoparticles
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| Creator |
Tanwar, Sanju
Awana, V. P. S. Singh, Surinder P. Pasricha, Renu |
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| Subject |
Applied Physics/Condensed Matter
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| Description |
We report the synthesis of phase pure, monodispersed Fe3O4 nanoparticles of size similar to 10 nm via chemical co-precipitation of ferrous and ferric ions, under controlled pH and temperature. The nanoparticles are oleic acid functionalized and hence dispersible in organic medium. The structure and morphology of nanoparticles are determined by analyzing XRD pattern and TEM micrographs, confirming the formation of phase pure Fe3O4 nanoparticles. The magnetization studies reveal the superparamagnetic behavior of the nanoparticles at room temperature. The changes in blocking temperatures (T-B) of magnetic nanoparticles with applied magnetic fields (H-ap), noted from the cusp of the zero-field-cooled magnetization, the indicate effects of dipole interactions. A decrease in blocking temperature from 95 K to 15 K has been observed on varying the magnetic field from 50 Oe to 5000 Oe. T-B versus H relation follows the equation T-B(H) = T-o(1 - (H/H-o))(m), i.e. the Neel-Brown model of magnetic relaxation in nanoparticles.
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| Publisher |
Springer Verlag
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| Date |
2012-08
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://npl.csircentral.net/3507/1/Magnetic%20Field%20Dependence.pdf
Tanwar, Sanju and Awana, V. P. S. and Singh, Surinder P. and Pasricha, Renu (2012) Magnetic Field Dependence of Blocking Temperature in Oleic Acid Functionalized Iron Oxide Nanoparticles. Journal of Superconductivity and Novel Magnetism, 25 (6). pp. 2041-2045. ISSN 1557-1939 |
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| Relation |
http://npl.csircentral.net/3507/
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